1. Field of the Invention
The present invention relates to a manufacturing method of a speaker for use in various audio equipments, and more specifically to a manufacturing method, in which main components of a speaker are welded for fixation by ultrasonic complex vibration, and also to a speaker produced by such a manufacturing method.
2. Description of the Related Art
In known methods of assembling a speaker, generally, constituent parts of a magnetic circuit are fixed to each other by means of adhesive, a frame is fixed to the magnetic circuit by means of screwing or crimping, a diaphragm is fixed to a surround by means of adhesive, and the surround is fixed to the frame by means of adhesive. Adhesive itself is very troublesome to manage, and fixation by adhesive raises various problems with respect to productivity and cost, such as variation in adhering process, difficulty in reducing curing time, and the like.
In order to solve the problems described above, a manufacturing method of a speaker is disclosed in, for example, Japanese Patent Application Laid-Open No. S57-13897. In the method disclosed, a surround is fixed to a frame by ultrasonic welding.
Another manufacturing method of a speaker is disclosed in Japanese Patent Application Laid-Open No. H11-122696. In the method, a spider is formed of a hot-cold processed woven fabric which is made of core-in-sheath type filaments each comprising a core of polyethylene terephthalate and a sheathing of polypropylene, and in which the intersecting portions of the filaments are firmly connected to each other due to the sheathing material heat-fused by the hot-cold process, and the spider thus formed is fixed by ultrasonic welding to a frame formed of resin. The spider thus structured can be produced at a lower temperature than conventionally, no special cooling system is required, and therefore existing equipments can be used as they are. And the spider structured and produced as described above is excellent in vital properties required, such as flexibility, chemical resistance, and adhesiveness.
In the first method, the material of the frame is required to be excellent in weldability with the surround so that the frame and the surround are duly fixed to each other by ultrasonic welding. And, in the second method, while it is proposed that the spider and the frame are fixed to each other by means of ultrasonic welding without using adhesive, there is no disclosure or even suggestion of the spider and frame materials which enable the spider and the frame to be duly ultrasonic-welded to each other, and also no such products as disclosed have been put to practical use.